* git://ozlabs.org/~paulus/gitk:
gitk: Remove boilerplate for configuration variables
gitk: Show detached HEAD if --all is specified
gitk: Do not depend on Cygwin's "kill" command on Windows
If HEAD is detached, 'gitk --all' does not show it. This is inconvenient
for frontend program, and for example git log does show the detached HEAD.
gitk uses git rev-parse to find a list of branches to show.
Apparently, the command does not include detached HEAD to output if
--all argument is specified. This has been discussed in [1] and stated
as expected behavior. So rev-parse's parameters should be tuned in gitk.
gitk: Do not depend on Cygwin's "kill" command on Windows
Windows does not necessarily mean Cygwin, it could also be MSYS. The
latter ships with a version of "kill" that does not understand "-f".
In msysgit this was addressed by shipping Cygwin's version of kill.
Properly fix this by using the stock Windows "taskkill" command instead,
which is available since Windows XP Professional.
Signed-off-by: Sebastian Schuberth <sschuberth@gmail.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
* dm/port2zos:
compat/bswap.h: detect endianness from XL C compiler macros
Makefile: reorder linker flags in the git executable rule
git-compat-util.h: support variadic macros with the XL C compiler
Tighten the logic to decide that an unreachable cruft is
sufficiently old by covering corner cases such as an ancient object
becoming reachable and then going unreachable again, in which case
its retention period should be prolonged.
* jk/prune-mtime: (28 commits)
drop add_object_array_with_mode
revision: remove definition of unused 'add_object' function
pack-objects: double-check options before discarding objects
repack: pack objects mentioned by the index
pack-objects: use argv_array
reachable: use revision machinery's --indexed-objects code
rev-list: add --indexed-objects option
rev-list: document --reflog option
t5516: test pushing a tag of an otherwise unreferenced blob
traverse_commit_list: support pending blobs/trees with paths
make add_object_array_with_context interface more sane
write_sha1_file: freshen existing objects
pack-objects: match prune logic for discarding objects
pack-objects: refactor unpack-unreachable expiration check
prune: keep objects reachable from recent objects
sha1_file: add for_each iterators for loose and packed objects
count-objects: use for_each_loose_file_in_objdir
count-objects: do not use xsize_t when counting object size
prune-packed: use for_each_loose_file_in_objdir
reachable: mark index blobs as SEEN
...
Teach difftool to exit when a diff tool returns a non-zero exit
code when either --trust-exit-code is specified or
difftool.trustExitCode is true.
Forward exit codes from invoked diff tools to the caller when
--trust-exit-code is used.
Suggested-by: Adri Farr <14farresa@gmail.com> Helped-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: David Aguilar <davvid@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
grep: add color.grep.matchcontext and color.grep.matchselected
The config option color.grep.match can be used to specify the highlighting
color for matching strings. Add the options matchContext and matchSelected
to allow different colors to be specified for matching strings in the
context vs. in selected lines. This is similar to the ms and mc specifiers
in GNU grep's environment variable GREP_COLORS.
Tests are from Zoltan Klinger's earlier attempt to solve the same
issue in a different way.
Signed-off-by: Rene Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
It took me a long time to notice the rider on the pack.threads
configuration option that it would multiple the memory consumption
by the number of CPUs in the machine. Clarify that the limit
applies per-thread.
Signed-off-by: Robert de Bath <rdebath@tvisiontech.co.uk> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Asciidoctor provides an extension implementing a backend-independent
macro for dealing with manpage links just like the linkgit macro. As
this is more likely to be up-to-date with future changes in Asciidoctor,
prefer using it over reimplementing in Git.
Documentation: refactor common operations into variables
The Makefile performs several very similar tasks to convert AsciiDoc
files into either HTML or DocBook. Move these items into variables to
reduce the duplication.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
compat/bswap.h: detect endianness from XL C compiler macros
There is no /usr/include/endian.h equivalent on z/OS, but the
compiler will define macros to indicate endianness on host and
target hardware. This adds a test for these macros as a last
resort for determining byte order.
Signed-off-by: David Michael <fedora.dm0@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Makefile: reorder linker flags in the git executable rule
The XL C compiler can fail due to mixing library path and object
file arguments, for example when linking git while building with
"gmake LDFLAGS=-L$prefix/lib".
Move the ALL_LDFLAGS variable expansion in the git executable rule
to be consistent with all the other linking rules, namely to have
LDFLAGS such as -L$where before the object files *.o being linked
together.
Signed-off-by: David Michael <fedora.dm0@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
git-compat-util.h: support variadic macros with the XL C compiler
When the XL C compiler is run with an appropriate language level or
suboption, it defines a feature test macro to indicate support for
variadic macros by defining __C99_MACRO_WITH_VA_ARGS C preprocessor
macro.
This was tested on z/OS, but it should also work on AIX according
to IBM documentation.
Signed-off-by: David Michael <fedora.dm0@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
difftool--helper: exit when reading a prompt answer fails
An attempt to quit difftool by hitting Ctrl-D (EOF) at its prompt does
not quit it, but is treated as if 'yes' was answered to the prompt and
all following prompts, which is contrary to the user's intent. Fix the
error check.
Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Allow us build with NO_PTHREADS=NoThanks compilation option.
* eb/no-pthreads:
Handle atexit list internaly for unthreaded builds
pack-objects: set number of threads before checking and warning
index-pack: fix compilation with NO_PTHREADS
Allow a temporary directory specified to be used while running "git
mergetool" backend.
* da/mergetool-temporary-directory:
t7610-mergetool: add test cases for mergetool.writeToTemp
mergetool: add an option for writing to a temporary directory
Allow "git mergetool --help" to run outside a Git repository.
* da/mergetool-tool-help:
difftool: don't assume that default sh is sane
mergetool: don't require a work tree for --tool-help
git-sh-setup: move GIT_DIR initialization into a function
mergetool: use more conservative temporary filenames
test-lib-functions: adjust style to match CodingGuidelines
t7610-mergetool: prefer test_config over git config
Tweak the names of the three throw-away files "git mergetool" comes
up with to feed the merge tool backend, so that a file with a
single dot in its name in the original (e.g. "hello.c") will have
only one dot in these variants (e.g. "hello_BASE_4321.c").
* da/mergetool-temporary-filename:
mergetool: use more conservative temporary filenames
The clean-up of this test script was long overdue and is a very
welcome change.
* da/mergetool-tests:
test-lib-functions: adjust style to match CodingGuidelines
t7610-mergetool: use test_config to isolate tests
t7610-mergetool: add missing && and remove commented-out code
t7610-mergetool: use tabs instead of a mix of tabs and spaces
The API to update refs have been restructured to allow introducing
a true transactional updates later. We would even allow storing
refs in backends other than the traditional filesystem-based one.
* rs/ref-transaction: (25 commits)
ref_transaction_commit: bail out on failure to remove a ref
lockfile: remove unable_to_lock_error
refs.c: do not permit err == NULL
remote rm/prune: print a message when writing packed-refs fails
for-each-ref: skip and warn about broken ref names
refs.c: allow listing and deleting badly named refs
test: put tests for handling of bad ref names in one place
packed-ref cache: forbid dot-components in refnames
branch -d: simplify by using RESOLVE_REF_READING
branch -d: avoid repeated symref resolution
reflog test: test interaction with detached HEAD
refs.c: change resolve_ref_unsafe reading argument to be a flags field
refs.c: make write_ref_sha1 static
fetch.c: change s_update_ref to use a ref transaction
refs.c: ref_transaction_commit: distinguish name conflicts from other errors
refs.c: pass a list of names to skip to is_refname_available
refs.c: call lock_ref_sha1_basic directly from commit
refs.c: refuse to lock badly named refs in lock_ref_sha1_basic
rename_ref: don't ask read_ref_full where the ref came from
refs.c: pass the ref log message to _create/delete/update instead of _commit
...
Beyond Compare version 4 works the same way as version 3, so rename
the existing "bc3" adaptor to just "bc", while keeping "bc3" as a
backward compatible wrapper.
Noticed-by: Olivier Croquette <ocroquette@free.fr> Helped-by: David Aguilar <davvid@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
.mailmap: add Stefan Bellers corporate mail address
Note that despite the private address being first and primary,
Google owns the copyright on this patch as any other patch I'll be
sending signed off by the sbeller@google.com address.
Signed-off-by: Stefan Beller <sbeller@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
A new filter to programatically edit the tail end of the commit log
messages.
* cc/interpret-trailers:
Documentation: add documentation for 'git interpret-trailers'
trailer: add tests for commands in config file
trailer: execute command from 'trailer.<name>.command'
trailer: add tests for "git interpret-trailers"
trailer: add interpret-trailers command
trailer: put all the processing together and print
trailer: parse trailers from file or stdin
trailer: process command line trailer arguments
trailer: read and process config information
trailer: process trailers from input message and arguments
trailer: add data structures and basic functions
Test scripts were taught to notice "-x" option to show shell trace,
as if the tests were run under "sh -x".
* jk/test-shell-trace:
test-lib.sh: support -x option for shell-tracing
t5304: use helper to report failure of "test foo = bar"
t5304: use test_path_is_* instead of "test -f"
Revert "archive: honor tar.umask even for pax headers"
This reverts commit 10f343ea814f5c18a0913997904ee11cd9b7da24, whose
output is no longer bit-for-bit equivalent from the older versions
of Git, which the infrastructure to (pretend to) upload tarballs
kernel.org uses depends on.
core.filemode is set automatically when a repo is created.
But when a repo is exported via CIFS or cygwin is mixed with Git for Windows
or Eclipse core.filemode may better be set manually to false.
Update and improve the documentation
Helped-by: Junio C Hamano <gitster@pobox.com> Signed-off-by: Torsten Bögershausen <tboegi@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
# ./t1304-default-acl.sh
ok 1 - checking for a working acl setup
ok 2 - Setup test repo
not ok 3 - Objects creation does not break ACLs with restrictive umask
#
# # SHA1 for empty blob
# check_perms_and_acl .git/objects/e6/9de29bb2d1d6434b8b29ae775ad8c2e48c5391
#
not ok 4 - git gc does not break ACLs with restrictive umask
#
# git gc &&
# check_perms_and_acl .git/objects/pack/*.pack
#
# failed 2 among 4 test(s)
1..4
on systems where USER isn't set. It's usually set by the login
process, but it isn't set when launching some Docker images. For
example:
$ docker run --rm debian env
HOME=/
PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
HOSTNAME=b2dfdfe797ed
'id -u -n' has been in POSIX from Issue 2 through 2013 [1], so I don't
expect compatibility issues.
Handle atexit list internaly for unthreaded builds
Wrap atexit()s calls on unthreaded builds to handle callback list
internally.
This is needed because on unthreaded builds, asyncs inherits parent's
atexit() list, that gets run as soon as the async exit()s (and again at
the end of async's parent process). That led to remove temporary files
too early.
Also remove a by-atexit-callback guard against this kind of issue in
clone.c, as this patch makes it redundant.
Fixes test 5537 (temporary shallow file vanished before unpack-objects
could open it)
BTW remove an unused variable in shallow.c.
Helped-by: Duy Nguyen <pclouds@gmail.com> Helped-by: Andreas Schwab <schwab@linux-m68k.org> Helped-by: Junio C Hamano <gitster@pobox.com> Signed-off-by: Etienne Buira <etienne.buira@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
This is a thin compatibility wrapper around
add_pending_object_with_path. But the only caller is
add_object_array, which is itself just a thin compatibility
wrapper. There are no external callers, so we can just
remove this middle wrapper.
Noticed-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Convert users of struct child_process to using the managed env_array for
specifying environment variables instead of supplying an array on the
stack or bringing their own argv_array. This shortens and simplifies
the code and ensures automatically that the allocated memory is freed
after use.
Signed-off-by: Rene Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
run-command: add env_array, an optional argv_array for env
Similar to args, add a struct argv_array member to struct child_process
that simplifies specifying the environment for children. It is freed
automatically by finish_command() or if start_command() encounters an
error.
Suggested-by: Jeff King <peff@peff.net> Signed-off-by: Rene Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
pack-objects: turn off bitmaps when we split packs
If a pack.packSizeLimit is set, we may split the pack data
across multiple packfiles. This means we cannot generate
.bitmap files, as they require that all of the reachable
objects are in the same pack. We check that condition when
we are generating the list of objects to pack (and disable
bitmaps if we are not packing everything), but we forgot to
update it when we notice that we needed to split (which
doesn't happen until the actual write phase).
The resulting bitmaps are quite bogus (they mention entries
that do not exist in the pack!) and can cause a fetch or
push to send insufficient objects.
Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
pack-objects: double-check options before discarding objects
When we are given an expiration time like
--unpack-unreachable=2.weeks.ago, we avoid writing out old,
unreachable loose objects entirely, under the assumption
that running "prune" would simply delete them immediately
anyway. However, this is only valid if we computed the same
set of reachable objects as prune would.
In practice, this is the case, because only git-repack uses
the --unpack-unreachable option with an expiration, and it
always feeds as many objects into the pack as possible. But
we can double-check at runtime just to be sure.
Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
When we pack all objects, we use only the objects reachable
from references and reflogs. This misses any objects which
are reachable from the index, but not yet referenced.
By itself this isn't a big deal; the objects can remain
loose until they are actually used in a commit. However, it
does create a problem when we drop packed but unreachable
objects. We try to optimize out the writing of objects that
we will immediately prune, which means we must follow the
same rules as prune in determining what is reachable. And
prune uses the index for this purpose.
This is rather uncommon in practice, as objects in the index
would not usually have been packed in the first place. But
it could happen in a sequence like:
1. You make a commit on a branch that references blob X.
2. You repack, moving X into the pack.
3. You delete the branch (and its reflog), so that X is
unreferenced.
4. You "git add" blob X so that it is now referenced only
by the index.
5. You repack again with git-gc. The pack-objects we
invoke will see that X is neither referenced nor
recent and not bother loosening it.
Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
There is currently no easy way to ask the revision traversal
machinery to include objects reachable from the index (e.g.,
blobs and trees that have not yet been committed). This
patch adds an option to do so.
Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
t5516: test pushing a tag of an otherwise unreferenced blob
It's not unreasonable to have a tag that points to a blob
that is not part of the normal history. We do this in
git.git to distribute gpg keys. However, we never explicitly
checked in our test suite that this actually works (i.e.,
that pack-objects actually sends the blob because of the tag
mentioning it).
It does in fact work fine, but a recent patch under
discussion broke this, and the test suite didn't notice.
Let's make the test suite more complete.
Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
traverse_commit_list: support pending blobs/trees with paths
When we call traverse_commit_list, we may have trees and
blobs in the pending array. As we process these, we pass the
"name" field from the pending entry as the path of the
object within the tree (which then becomes the root path if
we recurse into subtrees).
When we set up the traversal in prepare_revision_walk,
though, the "name" field of any pending trees and blobs is
likely to be the ref at which we found the object. We would
not want to make this part of the path (e.g., doing so would
make "git rev-list --objects v2.6.11-tree" in linux.git show
paths like "v2.6.11-tree/Makefile", which is nonsensical).
Therefore prepare_revision_walk sets the name field of each
pending tree and blobs to the empty string.
However, this leaves no room for a caller who does know the
correct path of a pending object to propagate that
information to the revision walker. We can fix this by
making two related changes:
1. Use the "path" field as the path instead of the "name"
field in traverse_commit_list. If the path is not set,
default to "" (which is what we always ended up with in
the current code, because of prepare_revision_walk).
2. In prepare_revision_walk, make a complete copy of the
entry. This makes the path field available to the
walker (if there is one), solving our problem.
Leaving the name field intact is now OK, as we do not
use it as a path due to point (1) above (and we can use
it to make more meaningful error messages if we want).
We also make the original "mode" field available to the
walker, though it does not actually use it.
Note that we still re-add the pending objects and free the
old ones (so we may strdup the path and name only to free
the old ones). This could be made more efficient by simply
copying the object_array entries that we are keeping.
However, that would require more restructuring of the code,
and is not done here.
Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git help everyday" to show the Everyday Git document.
* po/everyday-doc:
doc: add 'everyday' to 'git help'
doc: Makefile regularise OBSOLETE_HTML list building
doc: modernise everyday.txt wording and format in man page style
gitweb: use start_form, not startform that was removed in CGI.pm 4.04
CGI.pm 4.04 removed the startform method, which had previously been
deprecated in favour of start_form. Changes file for CGI.pm says:
4.04 2014-09-04
[ REMOVED / DEPRECATIONS ]
- startform and endform methods removed (previously deprecated,
you should be using the start_form and end_form methods)
Signed-off-by: Roland Mas <lolando@debian.org> Reviewed-by: Jakub Narębski <jnareb@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
mergetool: use more conservative temporary filenames
Avoid filenames with multiple dots so that overly-picky tools do
not misinterpret their extension.
Previously, foo/bar.ext in the worktree would result in e.g.
./foo/bar.ext.BASE.1234.ext
This can be improved by having only a single .ext and using
underscore instead of dot so that the extension cannot be
misinterpreted. The resulting path becomes:
./foo/bar_BASE_1234.ext
Suggested-by: Sergio Ferrero <sferrero@ensoftcorp.com> Helped-by: Junio C Hamano <gitster@pobox.com> Signed-off-by: David Aguilar <davvid@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
test-lib-functions: adjust style to match CodingGuidelines
Prefer "test" over "[ ]" for conditionals.
Prefer "$()" over backticks for command substitutions.
Avoid control structures on a single line with semicolons.
Signed-off-by: David Aguilar <davvid@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
mergetools/meld: make usage of `--output` configurable and more robust
Older versions of meld listed --output in `meld --help`.
Newer versions only mention `meld [OPTIONS...]`.
Improve the checks to catch these newer versions.
Add a `mergetool.meld.hasOutput` configuration to allow
overriding the heuristic.
Reported-by: Andrey Novoseltsev <novoselt@gmail.com> Helped-by: Junio C Hamano <gitster@pobox.com> Signed-off-by: David Aguilar <davvid@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
make add_object_array_with_context interface more sane
When you resolve a sha1, you can optionally keep any context
found during the resolution, including the path and mode of
a tree entry (e.g., when looking up "HEAD:subdir/file.c").
The add_object_array_with_context function lets you then
attach that context to an entry in a list. Unfortunately,
the interface for doing so is horrible. The object_context
structure is large and most object_array users do not use
it. Therefore we keep a pointer to the structure to avoid
burdening other users too much. But that means when we do
use it that we must allocate the struct ourselves. And the
struct contains a fixed PATH_MAX-sized buffer, which makes
this wholly unsuitable for any large arrays.
We can observe that there is only a single user of the
"with_context" variant: builtin/grep.c. And in that use
case, the only element we care about is the path. We can
therefore store only the path as a pointer (the context's
mode field was redundant with the object_array_entry itself,
and nobody actually cared about the surrounding tree). This
still requires a strdup of the pathname, but at least we are
only consuming the minimum amount of memory for each string.
We can also handle the copying ourselves in
add_object_array_*, and free it as appropriate in
object_array_release_entry.
Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
When we try to write a loose object file, we first check
whether that object already exists. If so, we skip the
write as an optimization. However, this can interfere with
prune's strategy of using mtimes to mark files in progress.
For example, if a branch contains a particular tree object
and is deleted, that tree object may become unreachable, and
have an old mtime. If a new operation then tries to write
the same tree, this ends up as a noop; we notice we
already have the object and do nothing. A prune running
simultaneously with this operation will see the object as
old, and may delete it.
We can solve this by "freshening" objects that we avoid
writing by updating their mtime. The algorithm for doing so
is essentially the same as that of has_sha1_file. Therefore
we provide a new (static) interface "check_and_freshen",
which finds and optionally freshens the object. It's trivial
to implement freshening and simple checking by tweaking a
single parameter.
Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
pack-objects: match prune logic for discarding objects
A recent commit taught git-prune to keep non-recent objects
that are reachable from recent ones. However, pack-objects,
when loosening unreachable objects, tries to optimize out
the write in the case that the object will be immediately
pruned. It now gets this wrong, since its rule does not
reflect the new prune code (and this can be seen by running
t6501 with a strategically placed repack).
Let's teach pack-objects similar logic.
Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
When we are loosening unreachable packed objects, we do not
bother to process objects that would simply be pruned
immediately anyway. The "would be pruned" check is a simple
comparison, but is about to get more complicated. Let's pull
it out into a separate function.
Note that this is slightly less efficient than the original,
which avoided even opening old packs, since no object in
them could pass the current check, which cares only about
the pack mtime. But the new rules will depend on the exact
object, so we need to perform the check even for old packs.
Note also that we fix a minor buglet when the pack mtime is
exactly the same as the expiration time. The prune code
considers that worth pruning, whereas our check here
considered it worth keeping. This wasn't a big deal. Besides
being unlikely to happen, the result was simply that the
object was loosened and then pruned, missing the
optimization. Still, we can easily fix it while we are here.
Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2. Not reachable, but recent (based on the --expire time).
3. Not reachable and not recent.
We keep objects from (1) and (2), but prune objects in (3).
The point of (2) is that these objects may be part of an
in-progress operation that has not yet updated any refs.
However, it is not always the case that objects for an
in-progress operation will have a recent mtime. For example,
the object database may have an old copy of a blob (from an
abandoned operation, a branch that was deleted, etc). If we
create a new tree that points to it, a simultaneous prune
will leave our tree, but delete the blob. Referencing that
tree with a commit will then work (we check that the tree is
in the object database, but not that all of its referred
objects are), as will mentioning the commit in a ref. But
the resulting repo is corrupt; we are missing the blob
reachable from a ref.
One way to solve this is to be more thorough when
referencing a sha1: make sure that not only do we have that
sha1, but that we have objects it refers to, and so forth
recursively. The problem is that this is very expensive.
Creating a parent link would require traversing the entire
object graph!
Instead, this patch pushes the extra work onto prune, which
runs less frequently (and has to look at the whole object
graph anyway). It creates a new category of objects: objects
which are not recent, but which are reachable from a recent
object. We do not prune these objects, just like the
reachable and recent ones.
This lets us avoid the recursive check above, because if we
have an object, even if it is unreachable, we should have
its referent. We can make a simple inductive argument that
with this patch, this property holds (that there are no
objects with missing referents in the repository):
0. When we have no objects, we have nothing to refer or be
referred to, so the property holds.
1. If we add objects to the repository, their direct
referents must generally exist (e.g., if you create a
tree, the blobs it references must exist; if you create
a commit to point at the tree, the tree must exist).
This is already the case before this patch. And it is
not 100% foolproof (you can make bogus objects using
`git hash-object`, for example), but it should be the
case for normal usage.
Therefore for any sequence of object additions, the
property will continue to hold.
2. If we remove objects from the repository, then we will
not remove a child object (like a blob) if an object
that refers to it is being kept. That is the part
implemented by this patch.
Note, however, that our reachability check and the
actual pruning are not atomic. So it _is_ still
possible to violate the property (e.g., an object
becomes referenced just as we are deleting it). This
patch is shooting for eliminating problems where the
mtimes of dependent objects differ by hours or days,
and one is dropped without the other. It does nothing
to help with short races.
Naively, the simplest way to implement this would be to add
all recent objects as tips to the reachability traversal.
However, this does not perform well. In a recently-packed
repository, all reachable objects will also be recent, and
therefore we have to look at each object twice. This patch
instead performs the reachability traversal, then follows up
with a second traversal for recent objects, skipping any
that have already been marked.
Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
sha1_file: add for_each iterators for loose and packed objects
We typically iterate over the reachable objects in a
repository by starting at the tips and walking the graph.
There's no easy way to iterate over all of the objects,
including unreachable ones. Let's provide a way of doing so.
Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
count-objects: do not use xsize_t when counting object size
The point of xsize_t is to safely cast an off_t into a size_t
(because we are about to mmap). But in count-objects, we are
summing the sizes in an off_t. Using xsize_t means that
count-objects could fail on a 32-bit system with a 4G
object (not likely, as other parts of git would fail, but
we should at least be correct here).
Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>